下列各组中，划线词语意思不同的两项是[ ]
A．不亦说乎/著书立说
B．三人行，必有我师焉/日行千里
C．必有我师焉/尊师重道
D．温故而知新/无缘无故
AD
Which of the following functions would the nurse expect to be unrelated to the placenta
A. Production of estrogen and progesterone.B. Detoxification of some drugs and chemicals.C. Exchange site for food, gases, and waste.D. Production of maternal antibodies.
A．U=vBl，流过固定电阻R的感应电流由b到d
B．U=vBl，流过固定电阻R的感应电流由d到b
C．U=vBl，流过固定电阻R的感应电流由b到d
D．U=vBl，流过固定电阻R的感应电流由d到b
vBl
vBl